Compressors are widely used in industrial and commercial operations. For example, a typical commercial gas turbine used to generate electrical power includes a compressor at the front, one or more combustors around the middle, and a turbine at the rear. A casing generally surrounds the compressor to contain a working fluid flowing through the compressor, and alternating stages of rotating blades and stationary vanes inside the casing progressively impart kinetic energy to the working fluid to produce a compressed working fluid at a highly energized state. Each rotating blade may be releasably connected to a rotor located along an axial centerline of the compressor, and each stator vane may be attached to a stator segment. For example, six stator segments may circumferentially surround the rotor, with three stator segments in each half of the casing. The casing may include a hook fit slot that extends circumferentially around the casing for each stage of stator vanes, and the stator segments may releasably slide into the hook fit slots.
Periodically, the stator vanes and stator segments in the compressor must be removed and/or replaced. Doing so typically requires at least partial removal of the casing surrounding the compressor to provide access to the stator vanes and stator segments. With the rotor still in place, however, access is somewhat restricted, and particular care must be taken to ensure that removal of the stator vanes and stator segments does not result in collateral damage to the rotor, casing, or adjacent rows of rotating blades. For example, a cutting tool may be manually inserted around the rotor to individually cut each stator vane, and once all stator vanes have been cut from a particular stator segment, the stator segment may be removed from the hook fit slots in the casing.
Occasionally, however, corrosion, creep, and/or other plastic deformation of the hook fit slots and/or stator segments prevent the stator segments from readily sliding out of the casing. For example, the stator segments may be constructed from carbon steel, and moisture from condensation, water washes, and other environmental factors may product corrosion that makes it extremely difficult to remove the stator segments from the hook fit slots. Rapid heating and cold water quenching of the stator segments is a very effective method to loosen the corrosion and remove the stator segments. However, the current method to heat the stator segments uses a torch or other open flame that may inadvertently damage the adjacent components and presents a fire hazard if exposed to rotor dams temporarily installed to protect the rotating blades. In addition, a single torch has a limited surface area for heating the stator segments, requiring several hours to heat a single stator segment. Therefore, an improved system and method for heating a stator segment would be useful.